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Full text of "Three new Afrotropical Cardiocondyla Emery, with a revised key to the workers (Hymenoptera Formicidae)."

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Boll. Soc. entomol. ital, 134 (2): 167 - 173 30 settembre 2002 

Fabrizio RIGATO 



Three new Afrotropical Cardiocondyla Emery, with a revised 

key to the workers 

(Hymenoptera Formicidae) 



Abstract - Three new Afrotropical species belonging to the myrmicine genus Cardiocondyla 
Emery are described: C. longinoda n. sp., C. tuciae n. sp. and C. yoruba n. sp. A revised key to 
the workers of Afrotropical Cardiocondyla is provided. 

Riassunto - Tre nuove Cardiocondyla afrotropicali, con una chiave aggiornata per le operaie. 
Tre nuove specie afrotropicali del genere mirmicino Cardiocondyla sono descritte: C. longinoda 
n. sp., C. luciae n. sp. and C. yoruba n. sp. Viene fornita anche una chiave aggiornata per le ope- 



Key words: Cardiocondyla, new species. Afrotropical, key 



Introduction 

Cardiocondyla is a moderate size genus with 38 known species (Bolton, 1995) 
occurring ali around the world; only the Australasian zoogeographical region seems to be 
without native taxa. Yet Seifert (pers. comm.) estimates that there are not less than 120 
species worldwide including many undescribed forms. 

Bolton (1982) revised the Afrotropical species and gave a key to the 9 species 
known from the area. 

Recently I received a single worker from Tanzania, which looked quite distinct 
from any other taxon known from the region. To this specimen I was able to add a few 
samples of two fUrther undescribed Afrotropical taxa borrowed from other specialists. 

In this paper I give a description of the new taxa and an updated key to the workers. 

Measurements and indices are as in Bolton (1982) and bave been taken using a 
Wild M3C stereomicroscope with an ocular graticule. 



Depositories 

BMNH: The Naturai History Museum, London, UK. 
MSNM: Museo Civico di Storia Naturale di Milano, Italy. 
SAM: South African Museum, Cape Town, South Africa. 

Cardiocondyla longinoda n. sp. (figs 1-3) 

HOLOTYPE WORKER. TL 2. 1, HL 0.49, HW 0.39, CI 80, SL 0.38, SI 97, PW 0.28, AL 0.60. 



1 68 Rigato 



A slender and pale species with long appendages. In full face view head relatively 
elongate with a hardly concave occipital margin and anterior clypeal lobe with an almost 
straight anterior edge. Maximum eye diameter 0.13 mm (14 ommatidia in the longest 
row). With the alitrunk in profile, the promesonotum forming a low convexity a little 
above the level of the propodeal dorsum; metanotal groove shallow. Pronotum seen from 
above with rounded humeri. Propodeum armed with two blunt and poorly developed 
teeth, which seen from above appear as dose and stubby tubercles. Petiole with a long 
low node, in dorsal view is about 1.5 times longer than wide; in posterior view the node 
is convex. Subpetiolar process barely discemable. Postpetiole seen from above about as 
long as wide, clearly narrower in front than behind and a little more than 1.5 times wider 
than the petiole. 

Mandibles shagreened and feebly longitudinally striolated, matt. Dorsum of head 
shagreened and fìnely blanketed with shallow and regular pubescence-bearing 
punctures. Promesonotal dorsum with a similar sculpture, but the punctures are poorly 
visible. Propodeum and sides of the alitrunk finely reticulate-punctate. Petiolar node and 
dorsum of the postpetiole fìnely shagreened; sides and peduncle of the petiole finely 
reticulate punctate. Dorsum of the gaster finely shagreened and matt with a silky 
appearance. 

Hairs present only on the anterior border of the clypeal lobe and at the tip of the 
gaster. Appressed pubescence well developed especially on the head and gaster 
Pubescent hairs on gaster distant from one another by about as much as their length or 
slightly less. 

Colour testaceous yellow, with a slightly duller gaster. 

Paratype workers. TL 2.0, HL 0.48-0.49, HW 0.37-0.38, CI 77-78, SL 0.36-0.37, SI 
95-100, PW 0.26-0.27, AL 0.57-0.59 (4 measured). 

Specimens belonging to the same series of the holotype are just slightly smaller in 
size, but consistent in every other respect. Specimens coming from Mkomazi Game 
Reserve have a darker colour, being more ferrugineous and with slightly infuscated head 
and gaster. Also, the shape of the petiolar node in profile is a little diflferent (fig. 3). In 
my opinion these variations could not justify any separation as a distinct taxon. 

Material examined. Holotype worker: TANZANIA: Kibaha, 7-vi-1988 (A.M. Varela) [BMNH]. 
Paratypes: 2 workers with the same data as the holotype [BMNH]. 1 worker: TANZANIA, 
Mkomazi Game Reserve, near Junction 9, 3°53'S 38°02'E, 8-V-1996 (H.G. Robertson) (SAM- 
HYM-C009896) [SAM]. 1 worker: TANZANIA, Mkomazi Game Reserve, Pangaro plot, 3°54'S 
37°47'E, 23-ÌV-1996 (H.G. Robertson) (SAM-HYM-C010399) [SAM]. 

CoMMENT. A distinctive taxon, easily recognisable by its slendemess, elongate and 
relatively low petiolar node and shagreened gaster. The latter recalls C. luciae (see 
below), but in other respects these ants are distinct. 

Derivatio nominis. An adjective formed by two latin words, "longus" (long) and 
"nodus" (knot or node), given to this species for the peculiar shape of the petiolar node. 



Three new Afrotropical Cardiocondyla Emery 1 69 



Cardiocondyla luciae n. sp. (figs 4-5) 

HOLOTYPE WORKER. TL 2. 1 , HL 0.50, HW 0.39, CI 78, SL 0.35, SI 90, PW 0.26, AL 0.58. 

A dark and slender species. In full face view head elongate, with almost parallel 
sides, clypeal lobe anteriorly straight, occiput notched in the middle. Maximum eye 
diameter 0.13 mm (14 ommatidia in the longest row). Scapes moderately long. With the 
alitrunk in profile the dorsal and anterior faces of the pronotum meeting at a distinct, 
blunt angle. Promesonotum almost fiat, about at the same level of the weakly convex 
propodeal dorsum, metanotal groove wide and shallow. In dorsal view the pronotum has 
slightly angular humeri, and promesonotal sides clearly convergent toward the metanotal 
groove. Propodeum armed with two short teeth, wide at the base. Petiole in profile with 
a rounded domed node; in dorsal view the node appears somewhat drop-shaped and a 
little longer than wide; in posterior view its apex is blunt conical. Subpetiolar process 
poorly developed. In dorsal view, postpetiole nearly twice as wide as the petiole, a little 
wider than long and slightly narrower in front than behind. 

Mandibles longitudinally striolate punctate, slightly shining. Dorsum of head 
shagreened, finely and regularly punctate; frons fmely longitudinally striolate. 
Promesonotal dorsum shagreened and finely punctate, but with less distinct punctures. 
Sides of the alitrunk, propodeum and sides of the petiole mostly finely reticulate 
punctate. Dorsum of petiolar node and postpetiole shagreened; the former hardly 
shining. Gaster dorsally finely shagreened, matt and with a silky appearance. 

Erect hairs present only on the anterior border of the clypeal lobe and at the tip of 
the gaster. Appressed pubescence well developed on the body and appendages, 
conspicuous on the head and especially on the gaster. On the first gastral tergite the 
pubescence is fairly abundant and a little denser than in C. longinoda (see above). 

Colour reddish brown, gaster duller; antennae with a darkened club. 

Material examined. Holotype worker: TANZANIA: Tarangire Nat. Park, Loborserit, xi- 
1998 (C. Polidori & L. Benaglio) [MSNM]. 

CoMMENT. This species is distinguished from ali other Afrotropical Cardiocondyla 
for its combination of dark colour, shagreened gaster, slender body and nearly fiat 
dorsum of the alitrunk. 

Derivatio nominis: a noun in the genitive case; this species is dedicated to Lucia 
Benaglio who collected the single specimen described. 

Cardiocondyla yoruba n. sp. (figs 6-7) 

Holotype worker. TL 1 .6, HL 0.42, HW 0.32, CI 76, SL 0.27, SI 84, PW 0.23, AL 0.45. 
In full face view head rectangular, longer than wide, the sides appearing slightly 
convergent in front of the eyes, anterior edge of the clypeal lobe hardly emarginate and 
occiput weakly concave. Maximum eye diameter 0.10 mm (8 ommatidia in the longest 
row). With the alitrunk in profile the promesonotum, as well as the dorsum of the 
propodeum, forming a low convexity; metanotal groove very shallow. Pronotum in 
dorsal view with rounded humeri and promesonotum with posteriorly weakly 



1 70 Rigato 



converging sides. Propodeal spines well developed, but short and with a broad base. 
Petiole in profile with a well developed node, in dorsal view the node is rounded and 
about as long as wide; in posterior view it appears widely rounded. Subpetiolar process 
small and protruding in front. Postpetiole in dorsal view about 1 .5 times wider than long 
and about 1.5 times wider than the petiole. 

Mandibles mostly smooth. Dorsum of the head regularly areolate, each 
pubescence-bearing areola finely sculptured. Dorsum of promesonotum similarly, but 
less regularly areolate; posteriorly and laterally the alitrunk becomes finely reticulate- 
punctate. Petiole and postpetiole shagreened on the dorsum, the petiole laterally finely 
reticulate-punctate. Gaster smooth with a very superficial sculpture near the base and 
regular pubescence-bearing punctulation. 

Erect hairs present only on the anterior clypeal margin and at the tip of the gaster. 
Appressed pubescence well developed on head, gaster and appendages, less abundant on 
the alitrunk. On the gaster, the pubescent hairs are about as distant from one another as 
their length or less. 

Colour testaceous with a brown gaster. Antennal club slightly infiiscated. 

Paratype workers. TL 1.6-1.7, HL 0.42-0.43, HW 0.31-0.33, CI 74-78, SL 0.26-0.27, 
SI 81-84, PW 0.21-0.24, AL 0.43-0.47 (9 measured). 

Very consistent with the holotype in size, measurements, sculpture and colour. 
Minor variations occur in the shape of the propodeal spines, concavity of the edge of the 
anterior clypeal lobe. The metanotal groove is sometimes fainter in profile. 

Material examined. Holotype worker: NIGERIA: Ibadan, IITA xi-1987 (J. Noyes) [BMNH]. 
Paratypes: 9 workers with the same data as the holotype. [BMNH] 

CoMMENT. No distinctive features, but with a combination of characters which make 
it different from any other Afrotropical Cardiocondyla. Its closest relative seems to be 
C. emeryi Forel from which C. yoruba may be easily separated by its minor size 
(compare measurements with those reported in Bolton, 1982), shallower metanotal 
groove and, in dorsal view, differently shaped petiolar node. 

Derivatio nominis. a noun in apposition: it is the name of the main human 
population living in SW Nigeria. 



Three new Afrotropical Cardiocondyla Emery 



171 







0.5 mm 





Figs 1-3. C. longinoda n. sp., worker (pilosity and scuipture omitted): I - profile of head, alitrunk, 

petiole and postpetiole (holotype); 2 - dorsal view of petiole and postpetiole (holotype); 3 - petiole 

in prode (paratype from Mkomazi Game Reserve). 

Figs 4-5. C. luciae n. sp. ^holotype), worker (pilosity and scuipture omitted): 4 - profile of head, 

alitrunk, petiole and postpetiole; 5 - dorsal view of petiole and postpetiole. 

Figs 6-7. C. yoruba n. sp. (holotype), worker (pilosity and scuipture omitted): 6 - profile of head, 

alitrunk, petiole and postpetiole; 7 - dorsal view of petiole and postpetiole. 



172 Rigato 



Revised key to the Afrotropical Cardiocondyla (workers) 

1 Propodeum in profile completely unarmed. Alitrunk without any trace of a metanotal groove. 
Petiole with an elongate peduncle and a low node. Size large (TL 2.7). (Angola) monardi 

- Propodeum in profile at least clearly angulate. Metanotal groove usually well developed. Petiole 
not so elongate. Size usually distinctly smaller 2 

2. With the head in full face view the scapes, when laid back, distinctly exceeding the occipital 
comers. (Sudan) nilotica 

With the head in full face view the scapes, when laid back, not exceeding the occipital comers, at 
most just reaching them 3 

3. Dorsal surfaces of head and alitrunk smooth and unsculptured everywhere, except for widely 
separated minute punctula on the head. Scape short (SI 74). (Ghana) sekhemka 

- Dorsal surfaces of head and alitrunk distinctly and finely sculptured. Scape longer (SI > 80) 

4 

4. Dorsum of the gaster distinctly finely shagreened, not smoother than head and alitrunk 5 

- Dorsum of the gaster not shagreened, smoother than head and alitrunk 6 

5 Petiolar node elongate, 1 .5 longer than wide in dorsal view and low, not domed, in profile. Colour 
mostly pale ferrugineous. Scape relatively long (SI 97-100). (Tanzania) longinoda 

Petiolar node not so elongate, less than 1 .5 longer than wide in dorsal view and domed in profile. 
Colour brown with a reddish tinge. Scape relatively short (SI 90). (Tanzania) ludae 

6 Propodeum in profile bluntly angulate to bidenticulate, never with a pair of strong teeth or spines. 
Scapes relatively long (SI 93-100). (Widespread in the Afrotropical region) shuckardi 

- Propodeum in profile at least distinctly bidentate. Scapes relatively short (SI 81-94) 7 

7 With the alitrunk in profile the dorsum approximately fiat before and behind the metanotal groove. 
Propodeal spines long and slender. (Cameroun) weserka 

With the alitrunk in profile the dorsum not fiat before and behind the metanotal groove, at least 
slightly convex. Propodeum armed with spines or teeth of various length 8 

8 Pronotai comers bluntly but conspicuously angular in dorsal view. (Ghana, Cameroun) 

neferka 

Pronotai comers rounded in dorsal view 9 

9 With alitrunk in profile the mesonotal dorsum abmptly changing slope posteriorly and descending 
steeply to the metanotal groove. Propodeal spines distinctly elongate. Head relatively wide, CI 79-86. 
(Pantropical tramp species) wroughtoniì 

With alitrunk in profile the mesonotal dorsum evenly curving into the metanotal groove. 
Propodeum with short spines or toothed. Head relatively narrow, CI 72-78 10 



Three new Afrotropical Cardiocondyla Emery 1 73 



10 Metanotal groove distinctly impresseci in profile. Petiolar node usually longer than wide in dorsal 
view, somewhat laterally compressed. Size larger, TL 1.7-2.1, HL > 0.44, AL > 0.47. (Cosmopolitan 

tramp species) emeryi 

Metanotal groove shallowly impressed in profile. Petiolar node globular in dorsal view, as long as 
Wide, never compressed. Size smaller, TL 1.6-1.7, HL 0.42-0.43, AL 0.43-0.46. (Nigeria) . . . yoruba 



ACKNOWLEDGEMENTS 

I wish to thank Barry Bolton (BMNH) and Hamish Robertson (S AM) for the loan of most 
material examined in this study. I am grateftil also to Lucia Benaglio and Cario Polidori (Milano) 
for the ants they coUected in Tanzania. Two referees provided useflil comments to the manuscript. 



References 

Bolton B., 1982. Afrotropical species of the myrmicine ant genera Cardiocondyla, Leptothorax, 
Melissotarsus, Messor and Cataulacus. BuUetin of the British Museum (Naturai History), 
Entomology series, 45: 307-370 

Bolton B., 1995. A taxonomic and zoogeographical census of the extant ant taxa. Journal of 
Naturai History, 29: 1037-1056 



Author 's address: 

F. Rigato, Museo Civico di Storia Naturale, Corso Venezia 55, 1-20121 Milano, Italy 
e-mail: Fabrizio.Rigato@comune.milano.it